I used a pencil tip type soldering iron and black zip ties as a filler. I used the iron to follow along the crack melting it together, I then cut some copper wire into about 1" peace, bent it into a U shape laying across the crack, use the iron to heat the copper wire and melt it in to the plastic. Do this the whole way down the crack, then take black zip ties and melt them over the copper and crack and into the peace your fixing, it reinforces and fixes the crack. I did this on the inside of the peace. Repaired my front fender and it's still holding strong, I also fixed my trunk and fairing like this.
I used a pencil tip type soldering iron and black zip ties as a filler. I used the iron to follow along the crack melting it together, I then cut some copper wire into about 1" peace, bent it into a U shape laying across the crack, use the iron to heat the copper wire and melt it in to the plastic. Do this the whole way down the crack, then take black zip ties and melt them over the copper and crack and into the peace your fixing, it reinforces and fixes the crack. I did this on the inside of the peace. Repaired my front fender and it's still holding strong, I also fixed my trunk and fairing like this.